Company Playpower Labs, LLC created these great apps:
Math Planet - Fun math game curriculum for kids, 2nd Grade Math Planet - Fun math game curriculum for kids, 3rd Grade Math Planet - Fun math game curriculum for kids, 1st Grade Math Planet - Fun math game curriculum for kids, 4th Grade Math Planet - Fun math game curriculum for kids, 5th Grade Math Planet - Fun math game curriculum for kids, Middle School Math Planet - Fun math game curriculum for kids, 1st Grade Math Pop - Fun math game for kids, 2nd Grade Math Pop - Fun math game for kids, 3rd Grade Math Pop - Fun math game for kids, 4th Grade Math Pop - Fun math game for kids, 5th Grade Math Pop - Fun math game for kids, Math Planet Pro, Math Pop Pro - Fun Math Practice for Grades 1-5, Math Pop - Fun Math Practice for Grades 1-5, LearnWorld: a brain building program for kids and parents, Math Planet - Fun math game curriculum for kids, Brain Builder Learning System, NeuroUX, NeuroLogger, Mathship Numberline, Solid Sleep, and others..
